The hard strain and stress of this life of effort and conflict made this man "Paul the aged" while he was not old in years. Such soul's agony and travail is indispensable for all high service of Christ. How can any true, noble Christian life be lived without continuous effort and continual strife? Up to the last particle of our power, it is our duty to work. As for the sleepy, languid, self-indulgent service of modern Christians, who seem to be chiefly anxious not to overstrain themselves, and to manage to win the race set before them without turning a hair, I am afraid that a large deduction will have to be made from it in the day that shall "try every man's work, of what sort it is." So much for the struggle; now for the strength. The toil and the conflict are to be carried on "according to His working, which worketh in me mightily." The measure of our power then is Christ's power in us. He whose presence makes the struggle necessary, by His presence strengthens us for it. He will dwell in us and work in us, and even our weakness will be lifted into joyful strength by Him. We shall be mighty because that mighty Worker is in our spirits. We have not only His presence beside us as an ally, but His grace within us. We may not only have the vision of our Captain standing at our side as we front the foe--an unseen presence to them, but inspiration and victory to us--but we may have the consciousness of His power welling up in our spirits and flowing, as immortal strength, into our arms. It is much to know that Christ fights for us; it is more to know that He fights in us.